H on the chain wheel stands for Hercules. Those forks may be beyond help. The frame may have too many problems also, but it's worth a try. It will take a lot of tweaking and testing to get it decent. A set of wheels to check the progress will really help, and make slight changes little by little.
That bike is a 50's Hercules, made by Hercules before Raleigh bought them all out. I had a bike like that, Herc also with a serial number 1556 BO. But mine also had a top tube that curved down from the top of the seat post to the front of the down tube.